Clinical trials done to date have focused on the efficacy of biventricular pacing (BVP) in the treatment of patients with congestive heart failure, Intraventricular conduction delay, dilated cardiomyopathies, and post cardiac surgery. However, studies done in post cardiac surgery patients are limited by their small sample size (4-22 patients with overall of 51 patients), non-randomized pacing protocol and by their inability to determine a definitive mechanism for the improved hemodynamics observed with BVP. Therefore, we propose to complete a pilot study aimed at determining both the magnitude of the hemodynamic benefit associated with BVP, if any. In addition, we will investigate changes in intra-ventricular septal motion as a possible mechanism for the previously observed changes in cardiac hemodynamics.